The present invention relates to a tow line release device and in particular to a safety release for water skiing tow lines which is adapted for quickly releasing the tow rope upon manual actuation of a trip rope from within the boat.
In many types of water skiing, it is desirable from a safety standpoint to be able to quickly release tension on the tow rope should the skier fall. In trick skiing, for example, one maneuver includes the placement of the skier's foot in the ski rope handle and he is towed without the use of his hands. Should the skier fall while in this position, he is susceptible to serious leg injuries such as pulled muscles, a twisted knee or a broken leg and may even be dragged under water before the driver of the boat reacts and is able to stop the boat. Aside from the potential for injury, the necessity for the skier to be constantly on guard so that he is able to pull his foot out of the handle or tow strap in the case of a fall reduces his concentration on performing the maneuver.
In addition to accidents resulting because of a trick skier being unable to release his foot from the rope, many accidents occur as a result of the skier becoming entangled in the rope as it is towed from the boat even though he has released the handle. Also, in the case where two or more skiers are being towed at the same time and one skier falls, the loose rope jerks about in the water quite violently and is liable to strike one of the other skiers.
In order to avoid the type of accidents described above, it has been found advantageous to provide for quick release of the tow rope by means of a trip mechanism operated manually from within the boat. One class of prior art devices comprises a pivotally mounted finger which hooks a terminal loop in the ski rope and is retained in engaging position by means of a latch. When the latch is released, tension on the ski rope pulls the finger open thereby releasing the rope. Examples of this type of device include U.S. Pat. Nos. 3,110,331; 3,133,521; 52,385; 1,115,807; 3,205,545 and 2,721,088.
A disadvantage to this type of device is that the finger requires tension on the rope for it to open so that if the ski rope is momentarily slack, as is often the case in trick skiing, the finger will fail to open quickly. Furthermore, the open finger may present an obstacle which can catch the rope and continue to drag the skier. Although the finger in the aforementioned U.S. Pat. No. 2,721,088 is designed such that it drops by gravity to its open position when released, this renders it inherently slow to open in the case of a slack rope. In fact, the rope may even interfere with its opening.
A further example of a prior art tow rope release is shown in U.S. Pat. No. 3,583,355 which discloses a clamp for gripping the free end of the ski rope or bridle. When the release lever is pulled, the jaws of the clamp open thereby releasing the tow rope. Due to the fact that the tow rope is frictionally rather than positively engaged, it may pull loose during skiing, especially if the skier is performing maneuvers which result in a high degree of tension being applied to the rope. Furthermore, clamping of the rope in this manner is likely to result in premature rope wear.
A further drawback to pivoted finger type hitches is that the force exerted by the tow rope on the finger is in a direction which urges it towards its open position. Should the latch mechanism fail, the finger will open thereby releasing the rope and causing the skier to fall. Since this is most likely to occur when maximum tension to the rope is being applied by the skier, as in the case of slalom skiing, the sudden release of tension is more likely to cause injury.